The present invention relates to folding multipurpose hand tools, and in particular relates to such a tool including provision for exchanging tool blades and to such a tool including folding scissors.
Various arrangements are known by which blades and tool bits can be exchanged or replaced in hand tools. In particular, Basham, U.S. Pat. No. 2,439,071, Copeman, U.S. Pat. No. 1,361,201, Gilbert, U.S. Pat. No. 4,073,057, Sizemore, et al., U.S. Pat. No. 4,391,043, and Frazer, U.S. Pat. No. 6,282,997 all disclose hand tools permitting exchange of blades or bits such as screwdriver bits, but the mechanisms for engaging replaceable blades or bits in the prior art have not been well adapted to use in mounting blades or bits so that they can easily be folded into a handle for stowage in a compact folded configuration of the tool.
Many different types of small folding scissors are known and are incorporated in various folding multipurpose hand tools. Many of such scissors include springs to open the handles, and thus open the blades, apart from each other, but folding such previously known scissors to permit stowage in a tool handle has typically required either that the spring be flexed and remain under load when the scissors are folded and stowed, or has required the handles to be pivoted wide apart from each other into opposing positions. These requirements have thus significantly limited the size, and thus the practical utility, of such scissors in the past. For example, in the scissors disclosed in Rivera, et al., U.S. Pat. No. 6,389,625, while there is an adequate spring to open the handles and blades apart from each other after a cutting stroke of the scissors, the handles and the blades must be separated into opposing positions to permit the scissors to be folded into the handle of the tool for stowage without the movable blade's handle having to engage and flex the spring.
What is needed, then, are an improved mechanism for securely mounting and releasing selected tool blades so that they can be extended for use or folded into a stowage configuration with respect to a handle of multipurpose tool, and an improved folding scissors that can be larger in size than previously available folding scissors, yet can be placed into a folded configuration free of tension in a spring, so that the scissors can be stowed in a small cavity in a tool handle.